What is a MB?

Whether you pay for your data on a monthly contract or on a “Pay As You Go” plan your data usage is most likely measured and charged by the megabyte or MB. So...

What is a megabyte (MB)? or kilobyte (kB)? or gigabyte (GB)?

From bytes to Gigabytes
One piece of digital information = 1 byte
1024 bytes = 1 kilobyte (kB)
1024 kB = 1 megabyte (MB)
1024 MB = 1 gigabyte (GB)

A byte is one piece of digital information. A megabyte (MB) is about 1,000,000 (one million) pieces of digital data.

This still isn't much help unless you know what this means in terms of an amount of text, a number of images or minutes of video. So let’s try and put it in a way that relates to how we typically consume data.


What do you get for 500MB?


If your contract has a monthly data limit (typically 500MB), what do you get for 500MB or about 16MB per day?


It depends! - on many things, the most significant of which is your own data usage habits. This is why you need to a tool like datasquasher to track and control your data consumption. However, here are a few guidelines and examples to help you measure what you might be using:

  1. Your data will be in the form of video, images or text. Typically, video is the most data-hungry followed by images and then text. But even within each category there are huge variations in files sizes.
  2. How well the originator of an app or website has optimised the content for use on a mobile device will vastly affect how much mobile data you use when browsing that website or using that app.


Video Streaming

Video is extremely data-hungry. This short, 56 second video clip in high quality will use 4.4MB of data.

Youtube: "Charlie bit my finger"

High Quality
Size 4.4MB
Watches per month 112*
Watches per day 4*
Standard Definition
Size 3.4MB
Watches per month 145*
Watches per day 5*

* based on a 500MB data plan over a 30 day month (16MB per day)

Emailing a video clip

This 43 second video clip taken on and emailed from a smartphone.

Standard Definition
Size 5.6MB
Watches per month 89*
Watches per day 3*

* based on a 500MB data plan over a 30 day month (16MB per day)


The data consumed when looking at a website on your mobile varies hugely depending on the mix of text, images and video and whether the site has been optimised for use on a mobile device.

Pick a website and check out your data usage using our online demo. Here are some examples:

Mail Online - Home page

5th November 2012, 15.06 hours

Size 4.0MB
Views per month 125*
Views per day 4*

* based on a 500MB data plan over a 30 day month (16MB per day)

Wired - Home page

6th November 2012, 11.00 hours

Size 1.3MB
Views per month 398*
Views per day 13*

* based on a 500MB data plan over a 30 day month (16MB per day)

BBC News - Home page

5th November 2012, 15.13 hours

The BBC News website is very well optimised for mobile devices:

Size 0.2MB
Views per month 3303*
Views per day 109*

* based on a 500MB data plan over a 30 day month (16MB per day)


Image quality and size have a significant impact on data usage. Nearly every website, whether it's a desktop or mobile-optimised site, will have numerous images that can consume a sizeable amount of your data allowance.

(File size)
Data used to send image +
4.1MB 1.1MB 0.18MB 0.06MB
Emails per month* 122 455 2778 8333
Emails per day* 4 15 91 274

* based on a 500MB data plan over a 30 day month (16MB per day)

+ Why more data is used to send an image or video

Sending email is text based, using SMTP (Simple Mail Transfer Protocol); this was around before the Internet as we know it, so they had to find a way of being able to send binary data (for images, videos & other attachments) too.

To do this, binary files are encoded into a text-based format. Because each text character can only hold a small amount of data, more are needed to represent the same file. Most files are encoded using MIME:

See http://en.wikipedia.org/wiki/MIME if you want to know more.

Sending images via email and instant messaging apps also use up your mobile data. The image quality you choose when sending an image (Original, Large, Medium or Small) makes a big difference to the data you use.

Added to this, sending images (or video) uses more data than the photo file size as the photo needs to be converted to travel by email ( + see right for a bit of “techy speak”).